Locomotive boiler firebox



Patented Oct. 1, 1940 i PATENT OFFICE LOCOMOTIVE BOILER FIREBOX Gust J. Christensen, Chicago, Ill., assignor to Locomotive Firebox Company, Chicago, Ill., a corporation of Delaware Application March 17,

Claims.

This invention relates to improvementsin locomotive `boiler reboxes `and it consists of the matters hereinafter described and more particularly pointed `out in the appended claims.

4One of the `objects of `the present invention is to provide a locomotive boiler rebox with a novel unitary tube arrangement for increasing the heating surface of the'rebox and for accelerating the water steaming and circulating action of the boiler as well as for insuring constant i ilooding of the crown sheet `and `which tube ar- Arangement is not only constructed to accommo- `4`date'iirebox `sheet movement but is relatively stiff, considered as aunit, to brace the crown H5sheet against downward pressures.

i Another object of the invention is to provide a *circulating tube `arrangement for use in a locot-motive boiler irebox, which is simple to make 4for low cost production from counterpart tubes secured together at one point, as a working unit, which while relatively flexible in one direction is f relatively stiiiin another direction.

The above `mentioned objects of the invention aswell as others together with the advantages thereof will more fully appear as the specicationi proceeds. uIn the drawing: I

Fig. l is `a longitudinal vertical sectional view i through a locomotive boiler rebox and adjacent boiler parts, embodying the preferred form of the invention, the plane vof the section being taken `on the line I-,I of Fig. 2. `Fig.` 2 is a transverse vertical sectional view through the same as taken on the line 2 2 of Fig. 1.

Fig. 3 isa detail horizontal sectional View on a somewhat enlarged scale as taken on the line Referring now in detail to that embodiment of 40 the invention illustrated `in the accompanying drawing: 5-5 indicate the side sheets of the firebox, 6 indicates the crown sheet, 'I indicates the front or ilue sheet and 8 indicates the back sheet thereof. It will be understood that the nrebox is positioned in the rear end of the associated boiler shell which includes the outer side sheets 9 9, top sheet I0, outer back sheet I I and front throat sheet I2. Portions of the back sheets 8 and II respectively are formed to provide a fuel door opening I3.

Several of the various sheets mentioned coact to form the side water legs I4, back water leg I5 and front throat I6 respectively, all bottomed by a mud ring I'I. The above is typical of a conventional locomotive boiler rear end structure 1939, Serial N0. 262,329`

and requires no further detailed description except to say that companion sheets are suitably staybolted.

To increase the effective evaporating surface area of the iirebox and the steaming and. water circulating efficiency of the associated boiler, the following arrangement is employed.

In the iireboX is provided a plurality of longitudinally spaced units, each extending transversely of the rebox and each comprising a pair of counterpart circulating tubes I8, with the tubes of each unit arranged upon opposite sides oi the longitudinal median plane of the rebox.

Each tube I8 includes an inlet portion It, an outlet portion 20 and an intermediate connecting portion 2l of reverse curve formation on the order of an ogee. The inlet portion has an inlet end 22 arranged at such an angle with respect to the associated side sheet that its extremity may be easily insertable nthrough a hole provided therefor in the side sheet and which extremity is welded in place as indicated at 23. rEhe inlet portion Iii which as shown herein is relatively straight, extends upwardly and inwardly from the inlet end at an inclination desired in the associated part of a nre arch which will be referred to later. The outlet portion 2t of each tube opens through the crown sheet and is welded therein as at 24. n

As shown herein the outer curved part of the portion 2l of each tube comprises upper, lower and intermediate curved parts and the intermediate curved part of one tube in each pair is engaged with and is securely connected tothe like part of the other tube in the pair comprising the unit. To provide a considerable area of er1-- gagement between said portions ci the tube, the outer curved part of the intermediate portion 2l of both tubes is attened as at 25 as appears in Fig. 3. When the flattened parts 25 of both tubes are so engaged, a line of welding 2t is run around the periphery of said engaged flattened parts. Jl/'hen the curved portions of a pair of tubes is thus welded together, they form a circulating unit having certain peculiar advantages in that while parts thereof move relatively to permit movement of rebox sheet parts, other parts act as a diaphragm to brace the crown sheet against undesired vertical downward movement under boiler pressures.

The structure comprising the units mentioned coact to support an arch indicated as a whole at 21 in Fig. 2. This arch is made up of transverse rows of brick each including an outer end brick 28, .an inner end brick 2S and intermediate brick 3l). The bricks are preferably curved transversely to the plane of the rows in which they are positioned as appears in Fig. 1. Each inner end brick is cut away as at 3| to reduce the width to; permit it to pass the curved intermediate parts of the tube as best appears in Fig. 3. As the intermediate portion of the tubes in each pair engage each other, the cut away corner structure above described for the inner end brick, leaves but relatively small triangular holes at the front and rear of the portions 2l of each pair of tubes which may be readily sealed with cement to make a substantially tight arch.

In the operation of the boiler, of which the rebox forms a part, the tubes absorb heat units from the products of combustion. Due to the thermic head thus produced, water and steam are discharged out through the outlet ends of the tubes into thfe boiler water space above the crown sheet and Water is drawn in from the legs at longitudinally spaced points therein. Thus a continuous circulatory action is established, the influence of which is exerted in all directions in the side water legs so as to produce a turbulence therein which prevents settling out of solids at the bottom of said legs. Also, due to the gushing or discharge of water from the outlet end of the tubes, a constant flooding of the crown sheet is effected which insures its complete submergence. Thus, even though the water level in the boiler falls below normal, it is assured that the same will at all times be covered with water.

The tubes, which are preferably made of seamless metal, may be bent to shape and may be flattened as before described, without cracking and may be easily installed in place.

While in describing the invention, I have referred in detail to the form, arrangement and construction of the parts thereof, the same is to be considered only in the illustrative sense and therefore, I do not wish to be limited thereto except as may be specifically set forth in the appended claims.

I claim as my invention:

1. A locomotive boiler rebox embodying therein a crown sheet and side sheets, water steaming and circulating means therein embodying a pair of circulating tubes, each tube including an inlet portion opening through an associated side sheet, an outlet portion opening through the crown sheet and a curved intermediate portion connecting said inlet and said outlet portions, said outlets being in spaced relation in the crown sheet, the curved intermediate portion of both tubes in said pair having parts on the outer side of the curve thereof formed to provide fiat engaging surfaces, and means connecting the tubes in said pair together at said flat engaging surfaces and vertically stiffening said pair of tubes as a unit.

2. A locomotive boiler rebox embodying therein a crown sheet and side sheets, water steaming and circulating means therein embodying a pair of circulating tubes, each tube including an inlet portion opening through an associated side sheet, an outlet portion opening through the crown sheet and a curved intermediate portion connecting said inlet and said outlet portions, said outlets being in spaced relation in the crown sheet, the curved intermediate portion of both tubes in said pair having parts on the outer side of the curve thereof formed to provide flat engaging surfaces that are welded together and vertically stiffen said pair of tubes as a unit.

3. A locomotive boiler rebox embodying therein a crown sheet and side sheets, water steaming and circulating means therein embodying a pair of circulating tubes, each tube including an inlet portion opening through an associated side sheet, an outlet portion opening through the crown sheet and an intermediate portion connecting said inlet and said outlet portions, said outlets being in spaced relation at the crown sheet, a part of the intermediate portion of one of the tubes in said pair being flattened to form an area for engagement by a co-acting area formed by a part of the other tube of said pair, and means connecting the tubes in said pair together at said engaged areas and vertically stiffening said pair of tubes as a unit.

4. A locomotive boiler rebox embodying therein a crown sheet and side sheets, water steaming and circulating means therein embodying a pair of circulating tubes, each tube including an inlet portion opening through an associated side sheet, an outlet portion opening through the crown sheet and an intermediate portion of reverse curvature connecting said inlet and said outlet portions, a part of the intermediate portion of one of the tubes in said pair being flattened tol form an area for engagement by a coacting area formed by a part of the other tube of said pair, and a line of welding extending about the periphery of the engaged areas of the tubes of said pair and vertically stiffening the same as a unit.

5. A locomotive boiler rebox embodying therein a crown sheet and side sheets, water steaming and circulating means therein embodying a pair of circulating tubes, each tube including an inlet portion opening through an associated side sheet, an outlet portion opening through the crown sheet and an intermediate portion of reverse curvature connecting said inlet and said outlet portions, a part of the intermediate portions of each tube in said pair being flattened to form engaging areas between said tubes, and means for securing said engaging areas of 4the tubes together and vertically stiffening them as a unit.

GUST J. CHRISTENSON. 

